Toward a "Cure"

There was a lot of discussion about "closing the loop" at this year's 70th annual Scientific Sessions of the American Diabetes Association. Closing the loop, in this context, means using technology to better normalize blood glucose control with little or no work from the person with diabetes. It was first proposed nearly 30 years ago when machines the size of a Volkswagen Beetle were used to both inject measured amounts of insulin and monitor blood glucose at the same time. But now the field is really moving quickly (and the machines are a lot smaller). It's exciting to see the progress.

Most people rarely think about the biological system that has evolved to keep our blood glucose in a normal range (about 70 to 140 mg/dl) 24 hours a day. Not only do multiple organ systems (pancreas, brain, liver) continuously sense glucose in our bodies, but we also have a continuous ability to secrete insulin to lower blood glucose or glucagon to raise it. When working properly, this highly complex set of processes is able to maintain normal blood glucose whether we are running a marathon or just sitting on the couch, eating a big piece of chocolate cake or just snacking on a carrot. Even the smartest diabetes researchers in the world still don't completely understand how this system communicates precisely enough to keep everything working well.

It's understandable that it's been so difficult to create a glucose management system that replaces what the body does. But we're getting a lot closer. One session at the ADA meeting was titled "The Artificial Pancreas—A Goal Within Reach?" Another lecture, presented outside of the meeting, was called "In Reach of a Cure for Diabetes—Closing the Loop." Both included presentations from the Juvenile Diabetes Research Foundation and discussed the advances in technology that are moving us closer to true continuous glucose management. While such technology would be a huge leap forward for people with insulin-dependent type 2 diabetes, it would approximate a "cure" for those with type 1, who have lost the ability to make insulin. (Click here for a look at where the quest for an artificial pancreas is headed.)

The first step, which has already been taken, is having an insulin pump communicate with a glucose sensor and shut off the insulin flow if blood glucose drops too low. The next step will probably be pumps that can regulate nocturnal blood glucose. This would allow people with type 1 diabetes (and their family members) to get a regular night of sleep without waking up every couple of hours and worrying about dangerous lows. The final step: a single pump that can use both insulin and glucagon to coordinate multi-hormonal injections with a continuous blood glucose sensor, maintaining normal blood glucose throughout the day.

While that last step is still a little ways off, the technology to allow it to happen is evolving quickly. So to the extent that blood glucose control between 70 and 140 mg/dl can "cure" diabetes, we're getting closer to a cure every day.